Tesla and SpaceX CEO Elon Musk has just published a paper sketching the basic concept for a transportation system that could theoretically launch passengers from Los Angeles to San Francisco in 30 minutes—four times faster than the high-speed rail system that California has been planning for decades. The full paper, including charts, maps, and technical specifications, is 57 pages and available in PDF here.

In Musk’s vision, the Hyperloop would transport people via aluminum pods enclosed inside of steel tubes. He describes the design as looking like a shotgun with the tubes running side by side for most of the journey and closing the loop at either end. These tubes would be mounted on columns 50 to 100 yards apart, and the pods inside would travel up to 800 miles per hour. Some of this Musk has hinted at before; he now adds that pods could ferry cars as well as people. “You just drive on, and the pod departs."

In his first interview about the project, Musk told Businessweek that he believes the project would be easier to build than California's high-speed rail tracks because it would be elevated, mostly following the path of I-5. It would also cost much less, he asserted. A version carrying people would run about $6 billion, while a version with larger pods capable of carrying whole cars would be $10 billion. California is set to spend some $70 billion on its high-speed rail system.

In his own brief blog post introducing the concept, Musk adds that he believes the hyperloop is the ideal solution for zipping people between cities that are less than 900 miles apart. Longer trips, he muses, would be better taken by supersonic plane.

We'll have more on how the hyperloop might work following Musk's press conference, which starts at 5 p.m. eastern.

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